Substrate liquid processing apparatus

ABSTRACT

A substrate liquid processing apparatus includes a liquid unit configured to process a liquid processing unit configured to process a substrate with multiple kinds of processing liquids, an exhaust pipe connected to the liquid processing unit, and configured to allow an exhaust gas from the liquid processing unit to flow therein, a plurality of individual exhaust pipes provided to correspond to at least one of the multiple kinds of processing liquids, and an exhaust switching unit connected to the exhaust pipe and the individual exhaust pipes, and configured to change a discharge destination of the exhaust gas flowing within the exhaust pipe to one of the individual exhaust pipes. The exhaust switching unit is positioned above the liquid processing unit.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional application of U.S. patent application Ser.No.14/924,916, filed on Oct. 28, 2015 which claims the benefit ofJapanese Patent Application No. 2014-223487 filed on Oct. 31, 2014, theentire disclosures of which are incorporated herein by reference.

TECHNICAL FIELD

The embodiments described herein pertain generally to a substrate liquidprocessing apparatus.

BACKGROUND

Conventionally, there is known a substrate liquid processing apparatusthat performs a liquid process on a substrate such as a silicon wafer ora compound semiconductor wafer.

In the substrate liquid processing apparatus, a liquid process usingplural kinds of processing liquids such as an acidic processing liquid,an alkaline processing liquid and an organic processing liquid may beperformed. In such a case, the substrate liquid processing apparatus isequipped with a plurality of individual exhaust pipes corresponding tothe processing liquids, respectively, and a switching unit configured toswitch a discharge destination of an exhaust gas to one of the pluralityof individual exhaust pipes (see Patent Document 1).

Patent Document 1: Japanese Patent Laid-open Publication No. 2013-033922

In the above-described prior art, however, there is still a room forimprovement in that a pressure variation of a liquid processing unit,which might be accompanied by the switching of the gas exhaust, needs tobe suppressed.

SUMMARY

In view of the foregoing, exemplary embodiments provide a substrateliquid processing apparatus, capable of suppressing a pressure variationof a liquid processing unit during a gas exhaust switching operation.

In one exemplary embodiment, a substrate liquid processing apparatusincludes a liquid processing unit, an exhaust pipe, a plurality ofindividual exhaust pipes and an exhaust switching unit. The liquidprocessing unit is configured to process a substrate with multiple kindsof processing liquids. The exhaust pipe is connected to the liquidprocessing unit, and configured to allow an exhaust gas from the liquidprocessing unit to flow therein. The individual exhaust pipes areprovided to correspond to at least one of the multiple kinds ofprocessing liquids. The exhaust switching unit is connected to theexhaust pipe and the individual exhaust pipes, and configured to changea discharge destination of the exhaust gas flowing within the exhaustpipe to one of the individual exhaust pipes. Further, the exhaustswitching unit is positioned above the liquid processing unit. Inanother exemplary embodiment, the exhaust switching unit includes aplurality of switching mechanisms, and an exterior air inlet chamberwhich communicates with each of exterior air suction openings of theswitching mechanisms.

According to the exemplary embodiment, it is possible to suppress thepressure variation of the liquid processing unit during the gas exhaustswitching operation.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description that follows, embodiments are described asillustrations only since various changes and modifications will becomeapparent to those skilled in the art from the following detaileddescription. The use of the same reference numbers in different figuresindicates similar or identical items.

FIG. 1 is a diagram illustrating an outline of a substrate processingsystem according to an exemplary embodiment;

FIG. 2 is a diagram illustrating an outline of a processing unit;

FIG. 3 is a diagram illustrating a gas exhaust path of the processingunit;

FIG. 4 is a schematic perspective view illustrating a processingstation;

FIG. 5 is a schematic side view illustrating the processing station;

FIG. 6 is a schematic plan view illustrating the processing station;

FIG. 7 is a schematic perspective view illustrating a gas exhaustswitching unit;

FIG. 8 is a schematic perspective view illustrating the gas exhaustswitching unit;

FIG. 9 is a diagram showing a configuration of the gas exhaust switchingunit;

FIG. 10 is a diagram showing a configuration of an exterior air inletchamber;

FIG. 11 is a diagram showing a state during a gas exhaust switchingoperation;

FIG. 12 is a diagram for describing a flow rate adjusting process;

FIG. 13 is a diagram for describing the flow rate adjusting process;

FIG. 14 is a flowchart for describing an example processing sequence ofa substrate processing performed in the substrate processing system;

FIG. 15 is a schematic side view illustrating a processing stationaccording to a first modification example; and

FIG. 16 is a schematic plan view illustrating a processing stationaccording to a second modification example.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part of the description. In thedrawings, similar symbols typically identify similar components, unlesscontext dictates otherwise. Furthermore, unless otherwise noted, thedescription of each successive drawing may reference features from oneor more of the previous drawings to provide clearer context and a moresubstantive explanation of the current exemplary embodiment. Still, theexemplary embodiments described in the detailed description, drawings,and claims are not meant to be limiting. Other embodiments may beutilized, and other changes may be made, without departing from thespirit or scope of the subject matter presented herein. It will bereadily understood that the aspects of the present disclosure, asgenerally described herein and illustrated in the drawings, may bearranged, substituted, combined, separated, and designed in a widevariety of different configurations, all of which are explicitlycontemplated herein.

Hereinafter, a substrate processing apparatus, an exhaust switching unitand a substrate liquid processing method according to exemplaryembodiments will be described with reference to the accompanyingdrawings. The exemplary embodiments are not limiting.

FIG. 1 is a plan view illustrating an outline of a substrate processingsystem provided with a processing unit according to an exemplaryembodiment of the present disclosure. In the following, in order toclarify positional relationships, the X-axis, Y-axis and Z-axis whichare orthogonal to each other will be defined. The positive Z-axisdirection will be regarded as a vertically upward direction.

As illustrated in FIG. 1, a substrate processing system 1 includes acarry-in/out station 2 and a processing station 3. The carry-in/outstation 2 and the processing station 3 are provided adjacent to eachother.

The carry-in/out station 2 is provided with a carrier placing section 11and a transfer section 12. In the carrier placing section 11, aplurality of carriers C is placed to accommodate a plurality ofsubstrates (semiconductor wafers in the present exemplary embodiment)(hereinafter, referred to as “wafers W”) horizontally.

The transfer section 12 is provided adjacent to the carrier placingsection 11, and provided with a substrate transfer device 13 and adelivery unit 14. The substrate transfer device 13 is provided with awafer holding mechanism configured to hold the wafer W. Further, thesubstrate transfer device 13 is movable horizontally and vertically andpivotable around a vertical axis, and transfers the wafers W between thecarriers C and the delivery unit 14 by using the wafer holdingmechanism.

The processing station 3 is provided adjacent to the transfer section12. The processing station 3 is provided with a transfer section 15 anda plurality of processing units 16. The plurality of processing units 16is arranged at both sides of the transfer section 15.

The transfer section 15 is provided with a substrate transfer device 17therein. The substrate transfer device 17 is provided with a waferholding mechanism configured to hold the wafer W. Further, the substratetransfer device 17 is movable horizontally and vertically and pivotablearound a vertical axis. The substrate transfer device 17 transfers thewafers W between the delivery unit 14 and the processing units 16 byusing the wafer holding mechanism.

The processing units 16 perform a predetermined substrate processing onthe wafers W transferred by the substrate transfer device 17.

Further, the liquid processing system 1 is provided with a controldevice 4. The control device 4 is, for example, a computer, and includesa control unit 18 and a storage unit 19. The storage unit 19 stores aprogram that controls various processings performed in the liquidprocessing system 1. The control unit 18 controls the operations of theliquid processing system 1 by reading and executing the program storedin the storage unit 19.

Further, the program may be recorded in a computer-readable recordingmedium, and installed from the recording medium to the storage unit 19of the control device 4. The computer-readable recording medium may be,for example, a hard disc (HD), a flexible disc (FD), a compact disc(CD), a magnet optical disc (MO), or a memory card.

In the substrate processing system 1 configured as described above, thesubstrate transfer device 13 of the carry-in/out station 2 first takesout a wafer W from a carrier C placed in the carrier placing section 11,and then places the taken wafer W on the transfer unit 14. The wafer Wplaced on the transfer unit 14 is taken out from the transfer unit 14 bythe substrate transfer device 17 of the processing station 3 and carriedinto a processing unit 16.

The wafer W carried into the processing unit 16 is processed by theprocessing unit 16, and then, carried out from the processing unit 16and placed on the delivery unit 14 by the substrate transfer device 17.After the processing of placing the wafer W on the delivery unit 14, thewafer W returns to the carrier C of the carrier placing section 11 bythe substrate transfer device 13.

Now, a configuration of the processing unit 16 will be elaborated withreference to FIG. 2. FIG. 2 is a diagram illustrating an outline of theprocessing unit 16.

As illustrated in FIG. 2, the processing unit 16 is provided with achamber 20, a substrate holding mechanism 30, a processing fluid supplyunit 40, and a recovery cup 50.

The chamber 20 accommodates the substrate holding mechanism 30, theprocessing fluid supply unit 40, and the recovery cup 50. A fan filterunit (FFU) 21 is provided on the ceiling of the chamber 20. The FFU 21forms a downflow in the chamber 20.

The substrate holding mechanism 30 is provided with a holding unit 31, asupport unit 32, and a driving unit 33. The holding unit 31 holds thewafer W horizontally. The support unit 32 is a vertically extendingmember, and has a base end portion supported rotatably by the drivingunit 33 and a tip end portion supporting the holding unit 31horizontally. The driving unit 33 rotates the support unit 32 around thevertical axis. The substrate holding mechanism 30 rotates the supportunit 32 by using the driving unit 33, so that the holding unit 31supported by the support unit 32 is rotated, and hence, the wafer W heldin the holding unit 31 is rotated.

The processing fluid supply unit 40 supplies a processing fluid onto thewafer W. The processing fluid supply unit 40 is connected to aprocessing fluid source 70.

The recovery cup 50 is disposed to surround the holding unit 31, andcollects the processing liquid scattered from the wafer W by therotation of the holding unit 31. A drain port 51 is formed on the bottomof the recovery cup 50, and the processing liquid collected by therecovery cup 50 is discharged from the drain port 51 to the outside ofthe processing unit 16. Further, an exhaust port 52 is formed on thebottom of the recovery cup 50 to discharge a gas supplied from the FFU21 to the outside.

Now, a gas exhaust path of the processing unit 16 will be elaboratedwith reference to FIG. 3. FIG. 3 is a diagram illustrating the gasexhaust path of the processing unit 16. In FIG. 3, components necessaryto explain the gas exhaust path of the processing unit 16 are mainlydepicted, and illustration of general components is appropriatelyomitted.

First, a configuration of the processing unit 16 according to thepresent exemplary embodiment will be discussed. As depicted in FIG. 3,the processing unit 16 includes the processing fluid supply unit 40having a nozzle 41; and a pipeline 42. One end of the pipeline 42 isconnected to the nozzle 41. The other end of the pipeline 42 is branchedinto plural lines, and an alkaline processing liquid supply source 71,an acidic processing liquid supply source 72, an organic processingliquid supply source 73 and a DIW supply source 74 are connected to theends of the branched lines, respectively. Further, valves 75 to 78 areprovided between the supply sources 71 to 74 and the nozzle 41,respectively.

The processing fluid supply unit 40 is configured to supply an alkalineprocessing liquid, an acidic processing liquid, an organic processingliquid and DIW (pure water of a room temperature) respectively fed fromthe corresponding supply sources 71 to 74 onto a surface (processingtarget surface) of the wafer W through the nozzle 41.

In the present exemplary embodiment, SC1 (a mixed solution of ammonia,hydrogen peroxide and water), HF (hydrofluoric acid) and IPA (isopropylalcohol) are used as the alkaline processing liquid, the acidicprocessing liquid and the organic processing liquid, respectively.However, it should be noted that the acidic processing liquid, thealkaline processing liquid and the organic processing liquid are notlimited to these examples.

Furthermore, in the present exemplary embodiment, the alkalineprocessing liquid, the acidic processing liquid, the organic processingliquid and the DIW are supplied from the single nozzle 41. However, theprocessing fluid supply unit 40 may be equipped with a plurality ofnozzles corresponding to the respective processing liquids.

Here, desirably, an alkaline exhaust gas discharged from the processingunit 16 when using the SC1, an acidic exhaust gas discharged from theprocessing unit 16 when using the HF and an organic exhaust gasdischarged from the processing unit 16 when using the IPA need to bedischarged individually in consideration of safety issues, etc., orsuppression of exhaust pipe contamination. For this reason, in thesubstrate processing system 1 according to the present exemplaryembodiment, there are provided separate gas exhaust paths for thealkaline exhaust gas, the acidic exhaust gas and the organic exhaustgas, respectively.

Now, a configuration of the gas exhaust path of the processing unit 16will be explained. As the gas exhaust path of the processing unit 16,the processing station 3 of the substrate processing system 1 isequipped with a first exhaust pipe 100, a second exhaust pipe 200 and anexhaust switching unit 300.

The first exhaust pipe 100 includes a plurality of individual exhaustpipes 101 to 103. The individual exhaust pipe 101 is a pipeline throughwhich the alkaline exhaust gas flows; the individual exhaust pipe 102, apipeline through which the acidic exhaust gas flows; and the individualexhaust pipe 103, a pipeline through which the organic exhaust gasflows. These individual exhaust pipes 101 to 103 are equipped withexhaust devices 151 to 153, respectively. Each of the exhaust devices151 to 153 may be implemented by a suction apparatus such as a pump.

In the present exemplary embodiment, at least a part of the individualexhaust pipes 101 to 103 is positioned above the processing unit 16. Aspecific layout of the individual exhaust pipes 101 to 130 will bedescribed later.

The second exhaust pipe 200 is configured to guide an exhaust gas fromthe processing unit 16 into the first exhaust pipe 100. One end of thesecond exhaust pipe 200 is connected to the exhaust port 52 of theprocessing unit 16, and the other end of the second exhaust pipe 200 isconnected, via the exhaust switching unit 300 to be described later, toa portion of the first exhaust pipe 100 positioned above the processingunit 16.

The second exhaust pipe 200 includes a horizontal portion 201horizontally extended from the exhaust port 52 of the processing unit16; and an upright portion 202 provided at a downstream side of thehorizontal portion 201 and vertically extended upwards. Further, a drainunit 250 for draining a liquid within the second exhaust pipe 200 to theoutside is provided at the bottommost position of the upright portion202.

The exhaust switching unit 300 is connected to the upright portion 202of the second exhaust pipe 200, and configured to switch a dischargedestination of the exhaust gas from the processing unit 16 to one of theindividual exhaust pipes 101 to 103. Like the first exhaust pipe 100,the exhaust switching unit 300 is also provided at a position above theprocessing unit 16.

The gas exhaust path of the processing unit 16 is configured asdescribed above, and the exhaust gas from the processing unit 16 isdischarged into one of the individual exhaust pipes 101 to 103 throughthe second exhaust pipe 200 and the exhaust switching unit 300.

Here, in the substrate processing system 1 according to the presentexemplary embodiment, at least a part of the first exhaust pipe 100 andthe exhaust switching unit 300 is positioned above the processing unit16, and the other end of the second exhaust pipe 200 is connected to theportion of the first exhaust pipe 100 positioned above the processingunit 16 via the exhaust switching unit 300. Accordingly, the exhaust gasfrom the processing unit 16 is discharged into the first exhaust pipe100 through the exhaust switching unit 300 after flowing upwards in theupright portion 202 of the second exhaust pipe 200.

The exhaust gas from the processing unit 16 may contain mist. Since themist is heavier than a gas, it is difficult for the mist to flow upwardswithin the upright portion 202, as compared to the exhaust gas.Accordingly, while the exhaust gas containing the mist flows in theupright portion 202, the exhaust gas which tends to easily flow upwardsin the upright portion 202 and the mist which cannot easily flow upwardsin the upright portion 202 are efficiently separated from each other.Then, the exhaust gas is discharged to the outside from the firstexhaust pipe 100 via the exhaust switching unit 300 provided above theupright portion 202, whereas the mist is liquefied by a temperaturereduction and, then, discharged to the outside through the drain unit250 provided at the bottommost position of the upright portion 202.

As stated above, in the substrate processing system 1 according to thepresent exemplary embodiment, the gas exhaust path of the processingunit 16 includes the upright portion 202, and the exhaust gas from theprocessing unit 16 is guided upwardly. Accordingly, it is possible toimprove the gas-liquid separation of the exhaust gas discharged from theprocessing unit 16. Furthermore, since the gas-liquid separation isperformed within the upright portion 202, contaminants or impuritiesgenerated from the mist can be suppressed from adhering to the exhaustswitching unit 300 provided at the downstream side of (provided above)the upright portion 202.

Moreover, once the mist is liquefied, the liquid falls down within theupright portion 202 to be collected at the bottommost position of theupright portion 202. Thus, by providing the drain unit 250 at thebottommost position of the upright portion 202, the liquid within thesecond exhaust pipe 200 can be discharged to the outside efficiently.

Here, the bottommost position of the upright portion 202 in the presentexemplary embodiment corresponds to a corner portion between thehorizontal portion 201 and the upright portion 202. When the mistflowing in the second exhaust pipe 200 moves from the horizontal portion201 to the upright portion 202, the mist may collide with the cornerportion to be liquefied. As such, by providing the corner portionbetween the horizontal portion 201 and the upright portion 202 andproviding the drain unit 250 at the corner portion, the liquid withinthe second exhaust pipe 200 can be more efficiently collected.

In addition, the substrate processing system 1 may be further equippedwith a cooling water discharging unit configured to discharge coolingwater into the upright portion 202 from above it. With thisconfiguration, it is possible to liquefy the mist within the uprightportion 202 more actively by cooling it with the cooling water.

Since the alkaline exhaust gas, the acidic exhaust gas and the organicexhaust gas all flow within the second exhaust pipe 200, there is alikelihood that the inside of the second exhaust pipe may becontaminated with, for example, salt generated therein. As a solution tothis problem, the substrate processing system 1 may be equipped with acleaning water discharging unit configured to discharge cleaning waterinto the second exhaust pipe 200. With this configuration, thecontaminant within the second exhaust pipe 200 can be removed by thecleaning water.

In the present exemplary embodiment, the drain unit 250 is provided atthe bottommost position of the upright portion 202 (i.e., at the cornerportion between the horizontal portion 201 and the upright portion 202).Alternatively, however, the drain unit 250 may be provided at thehorizontal portion 201. Furthermore, though the second exhaust pipe 200is described to have the horizontal portion 201, the second exhaust pipe200 may not necessarily have the horizontal portion 201.

In addition, the present exemplary embodiment has been described for theexample case where the upright portion 202 is vertically extended.However, the upright portion 202 may be extended diagonally, spirally,in a zigzag shape, or the like. By forming the upright portion 202 tohave these shapes, the length of the upright portion 202 can beincreased, as compared to the case where it is extended vertically. Asthe length of the upright portion 202 increases, a greater amount ofmist may be liquefied in the upright portion 202 by a temperaturereduction, and, thus, the gas-liquid separation can be further improved.

Now, the layout of the first exhaust pipe 100, the second exhaust pipe200 and the exhaust switching unit 300 described above will beelaborated with reference to FIG. 4 to FIG. 7. FIG. 4 is a schematicperspective view of the processing station 3. Further, FIG. 5 is aschematic side view of the processing station 3, and FIG. 6 is aschematic plan view thereof. Here, the side view is a diagramillustrating the processing station 3 seen from a positive Y-axisdirection, and the plan view is a diagram illustrating the processingstation 3 seen from a negative Z-axis direction. Further, in FIG. 4,illustration of a configuration of the processing station 3 which islocated at the side of the positive Y-axis direction with respect to thetransfer section 15 (see FIG. 1) is omitted.

As depicted in FIG. 4 and FIG. 5, the processing station 3 includes aframe structure 400 having a multiple number of column portions 401 anda multiplicity of beam portions 402. A plurality of processing units 16and a plurality of valve boxes 60 are accommodated in spaces formed bythe column portions 401 and the beam portions 402.

The plurality of processing units 16 are arranged in parallel along thetransfer section 15 and vertically stacked in two levels. Each of theplurality of valve boxes 60 is a container in which the valves 75 to 78(see FIG. 3) and the like are accommodated, and is provided under eachprocessing unit 16.

In the following, among the processing units 16 vertically stacked intwo levels, each processing unit 16 provided at the upper level will bereferred to as “processing unit 16U”, and each processing unit 16provided at the lower level will be referred to as “processing unit16L.” Further, though the processing units 16 are vertically stacked intwo levels in the present exemplary embodiment, the stacking number ofthe processing units 16, i.e., the number of the vertical levels of theprocessing units 16 may not be limited to two. Moreover, FIG. 4 to FIG.6 illustrate an example layout where five processing units 16 arearranged in parallel, the number of the processing units 16 arranged inparallel may not be limited to five.

The individual exhaust pipes 101 to 103 of the first exhaust pipe 100are placed on the frame structure 400, and the exhaust switching units300 respectively corresponding to the processing units 16 are placed onthe individual exhaust pipes 101 to 103.

As stated, in the substrate processing system 1 according to theexemplary embodiment, the individual exhaust pipes 101 to 103 and theexhaust switching units 300 are placed at the outside of the framestructure 400. Accordingly, the assembly of the frame structure 400, theassembly of the individual exhaust pipes 101 to 103, and the assembly ofthe exhaust switching units 300 can be delivered individually.Therefore, the transfer or the installation of these components can beeased.

Moreover, in the substrate processing system 1 according to theexemplary embodiment, since the first exhaust pipe 100 and the exhaustswitching units 300 are disposed at the outside of the frame structure400, the configuration of the first exhaust pipe 100 and the exhaustswitching units 300 can be easily modified depending on the substrateprocessing kinds.

By way of example, when using only two kinds of processing liquids (thealkaline processing liquid and the acidic processing liquid), a firstexhaust pipe 100 without having the individual exhaust pipe 103 andexhaust switching units 300 corresponding to this first exhaust pipe 100may be easily provided on the frame structure 400. As described,according to the substrate processing system 1 of the exemplaryembodiment, the degree of freedom in design can be improved.

Furthermore, in the substrate processing system 1 according to thepresent exemplary embodiment, it is easier to provide an extra space 410(see FIG. 5) within the frame structure 400, as compared to the casewhere the first exhaust pipe 100 and the exhaust switching units 300 areaccommodated within the frame structure 400. The extra space 410 may beprovided at the bottommost portion of the frame structure 400, and maybe used as a space for accommodating various supply sources such as thealkaline processing liquid supply source 71 and the acidic processingliquid supply sources 72.

Further, the exhaust switching units 300 according to the exemplaryembodiment are placed on the individual exhaust pipes 101 to 103. Thatis, the exhaust switching units 300 are located at the topmost portionof the processing station 3. With this configuration, an operator caneasily perform replacement or maintenance of the exhaust switching units300. Here, the exhaust switching units 300 needs to be located at leastabove the processing units 16. For example, the exhaust switching units300 may be disposed under the individual exhaust pipes 101 to 103.

As depicted in FIG. 4 and FIG. 5, the first exhaust pipe 100 is placedabove the processing units 16U arranged at the topmost level, and secondexhaust pipes 200 U and 200L corresponding to the upper processing units16U and the lower processing units 16B, respectively, are connected tothe first exhaust pipe 100 via corresponding exhaust switching units300U and 300L, respectively.

As stated above, in the substrate processing system 1 according to theexemplary embodiment, the upper processing units 16U and the lowerprocessing units 16L share the first exhaust pipe 100. Thus, as comparedto the case where individual first exhaust pipes 100 are provided forthe respective upper processing units 16U and lower processing units16L, a manufacturing cost of the substrate processing system 1 can bereduced.

In addition, as depicted in FIG. 6, the substrate processing system 1includes a first exhaust pipe 100 corresponding to processing units 16located at the side of the negative Y-axis direction with respect to thetransfer section 15; and a first exhaust pipe 100 corresponding toprocessing units 16 located at the side of the positive Y-axis directionwith respect to the transfer section 15. Each first exhaust pipe 100 isplaced above a region where the corresponding processing units 16 aredisposed.

Here, among the multiple second exhaust pipes 200, the second exhaustpipes 200U connected to the upper processing units 16U and the secondexhaust pipes 200L connected to the lower processing units 16L arearranged at the same side of these processing units 16U and 16L. By wayof example, FIG. 5 illustrates an example configuration where the secondexhaust pipes 200U and 200L are disposed at the right side of theprocessing units 16U and 16L when the processing station 3 is seen fromthe positive Y-axis direction.

Moreover, among the plurality of exhaust switching units 300, theexhaust switching units 300U corresponding to the upper processing units16U and the exhaust switching units 300L corresponding to the lowerprocessing units 16L are alternately arranged in an arrangementdirection of the processing units 16.

Each exhaust processing unit 300U and each exhaust processing unit 300Lhave the same configuration, and are arranged to face each other. Toelaborate, as depicted in FIG. 5, when the processing station 3 is seenfrom the positive Y-axis direction, the exhaust switching unit 300Ucorresponding to the upper processing unit 16U and the exhaust switchingunit 300L corresponding to the lower processing unit 16L are arranged inline symmetry with respect to the second exhaust pipes 200U and 200L, asa central line X, which are connected to the processing units 16U and16L, respectively.

As stated above, in the substrate processing system 1, the secondexhaust pipe 200U connected to the upper processing unit 16U and thesecond exhaust pipe 200L connected to the lower processing unit 16 arearranged at the same side of the processing units 16U and 16L.Furthermore, the exhaust switching unit 300U corresponding to the upperprocessing unit 16U and the exhaust switching unit 300L corresponding tothe lower processing unit 16L are arranged to face each other in linesymmetry with respect to the second exhaust pipes 200U and 200L as thecentral line X. With this layout, the second exhaust pipes 200U and 200Lor the exhaust switching units 300U and 300L can be commonly shared atthe upper level and the lower level.

Moreover, the exhaust switching unit 300U and the exhaust switching unit300L may not necessarily be disposed to face each other. By way ofexample, the exhaust switching unit 300U and the exhaust switching unit300L may be arranged to face the same direction. In such a case, forexample, the second exhaust pipe 200L connected to the lower processingunit 16L may be vertically extended and coupled to the exhaust switchingunit 300L, whereas the second exhaust pipe 200U connected to the upperprocessing unit 16U may be diagonally extended and coupled to theexhaust switching unit 300U.

Now, a configuration of the exhaust switching unit 300 will be explainedwith reference to FIG. 7 and FIG. 8. FIG. 7 and FIG. 8 are schematicperspective views of the exhaust switching unit 300.

As depicted in FIG. 7 and FIG. 8, each of the exhaust switching units300U and 300L includes an exhaust gas inlet chamber 310, a plurality ofswitching mechanisms 320_1 to 320_3, an exterior air inlet chamber 330,and a plurality of outlet portions 340. Further, each of the exhaustswitching units 300U and 300L further includes an exterior air suctionpipe 350, a differential pressure port 360, and an exhaust gas flow ratecontroller 370.

The exterior air suction pipe 350 of the exhaust switching unit 300L(300U) is connected to the second exhaust pipe 200L (200U) (see FIG. 8),and the outlet portions 340 of the exhaust switching unit 300L (300U)are connected to the individual exhaust pipes 101 to 103, respectively(see FIG. 7). An exhaust gas from the second exhaust pipe 200L (200U) isintroduced into one of the switching mechanisms 320_1 to 320_3 throughthe differential pressure port 360, the exhaust gas flow rate controller370 and the exhaust gas inlet chamber 310 (see FIG. 8), and thendischarged into one of the individual exhaust pipes 101 to 103 throughthe outlet portion 340 from the corresponding one of the switchingmechanisms 320_1 to 320_3.

Further, in each of the exhaust switching unit 300U and 300L, theexhaust gas inlet chamber 310, the switching mechanisms 320_1 to 320_3,the exterior air inlet chamber 330, the outlet portions 340, theexterior air suction pipe 350, the differential pressure port 360 andthe exhaust gas flow rate controller 370 are unitized. Accordingly, theexhaust switching unit 300U and 300L can be easily attached to ordetached from the individual exhaust pipes 101 to 103 or the secondexhaust pipe 200.

The exhaust gas inlet chamber 310 includes a hollow box-shaped main body311, and a multiple number of communication openings (not shown)communicating with respective exhaust gas suction openings 322 of theswitching mechanisms 320_1 to 320_3 are formed at a side surface of themain body 311 which faces the switching mechanisms 320_1 to 320_3.Further, a communication opening (not shown) communicating with theexhaust gas flow rate controller 370 is formed at a bottom surface ofthe main body 311. The exhaust gas inlet chamber 310 having thisconfiguration is configured to introduce the exhaust gas, which is flownfrom the second exhaust pipe 200 via the exterior air suction pipe 350,the differential pressure port 360 and the exhaust gas flow ratecontroller 370 to be described later, into the switching mechanisms320_1 to 320_3.

Here, the exhaust gas introduced into the exhaust gas inlet chamber 310from the exhaust gas flow rate controller 370 is flown into one of theswitching mechanisms 320_1 to 320_3 after colliding with a top surfaceof the exhaust gas inlet chamber 310. Therefore, even if the mist iscontained in the exhaust gas introduced into the exhaust gas inletchamber 310, the mist can be liquefied by the collision with the topsurface of the exhaust gas inlet chamber 310, so that the mist can besuppressed from reaching the switching mechanisms 320_1 to 320_3.

Furthermore, in the present exemplary embodiment, the exhaust gas inletchamber 310 is implemented by a box body having a rectangular shape.However, the shape of the exhaust gas inlet chamber 310 may not belimited to the rectangle. By way of non-limiting example, the exhaustgas inlet chamber 310 may be implemented by a box body having acylindrical shape. By forming the exhaust gas inlet chamber 310 to havethe cylindrical shape, it is possible to share members or lines formedof pipes, for example. In this case as well where the exhaust gas inletchamber 310 has the cylindrical shape, the exhaust gas introduced intothe exhaust gas inlet chamber 310 is flown into one of the switchingmechanisms 320_1 to 320_3 after colliding with an inner surface of theexhaust gas inlet chamber 310. Therefore, as in the case where theexhaust gas inlet chamber 310 has the rectangular shape, the mist can beliquefied by colliding with the inner surface of the exhaust gas inletchamber 310.

In the present exemplary embodiment, the exhaust gas inlet chamber 310is formed of the box body. However, the exhaust gas inlet chamber 310may not necessarily be formed of the box body. By way of non-limitingexample, the exhaust gas inlet chamber 310 may be implemented by apipeline one end of which is connected to the exhaust gas flow ratecontroller 370 and the other end of which is branched into plural branchlines respectively connected to the switching mechanisms 320_1 to 320_3.

The switching mechanisms 320_1 to 320_3 correspond to the individualexhaust pipes 101 to 103, respectively, and the switching mechanisms320_1 to 320_3 are arranged in the same direction (Y direction) as thearrangement direction of the individual exhaust pipes 101 to 103. Theexhaust gas inlet chamber 310, the exterior air inlet chamber 330 andthe outlet portion 340 are connected to each of the switching mechanisms320_1 to 320_3. The exhaust gas inlet chamber 310 and the exterior airinlet chamber 330 are connected to one side surface of each of theswitching mechanisms 320_1 to 320_3 with a preset vertical intervaltherebetween. Further, each of the outlet portions 340 is connected to aside surface of the corresponding one of the switching mechanisms 320_1to 320 _(—) opposite from the side surface thereof to which the exhaustgas inlet chamber 310 and the exterior air inlet chamber 330 areconnected.

Each of the switching mechanisms 320_1 to 320_3 is configured to switch,by operating a valve body provided therein, a state where the exhaustgas inlet chamber 310 communicates with the outlet portion 340 and astate where the exterior air inlet chamber 330 communicates with theoutlet portion 340. Here, internal configuration of the switchingmechanisms 320_1 to 320_3 will be discussed with reference to FIG. 9.FIG. 9 illustrates a configuration of the exhaust switching unit 300.

As depicted in FIG. 9, each of the switching mechanisms 320_1 to 320_3includes a main body 321. The main body 321 has a cylindrical internalspace both ends of which are closed. An exhaust gas suction opening 322communicating with the exhaust gas inlet chamber 310, an exterior airsuction opening 323 communicating with the exterior air inlet chamber330 and an outlet opening 324 communicating with the outlet portion 340are formed at an inner peripheral surface of the main body 321.

A valve body 325 configured to be slidably moved along the innerperipheral surface of the main body 321 is provided in the internalspace of the main body 321. The valve body 325 is driven by a drivingunit 326 (see FIG. 7) provided outside the switching mechanisms 320_1 to320_3. The driving unit 326 is controlled by the control unit 18.

Among the exhaust gas suction opening 322, the exterior air suctionopening 323 and the outlet opening 324 formed at the inner peripheralsurface of the main body 321, either one of the exhaust gas suctionopening 322 or the exterior air suction opening 323 is blocked by thevalve body 325. That is, only one of the exhaust gas inlet suctionopening 322 and the exterior air suction opening 323 is allowed tocommunicate with the outlet opening 324. In each of the switchingmechanisms 320_1 to 320_3, as the valve body 325 is slid along the innerperipheral surface of the main body 321, the opening communicating withthe outlet opening 324 is switched from the exhaust gas suction opening322 to the exterior air suction opening 323, or from the exterior airsuction opening 323 to the exhaust gas suction opening 322. That is,each of the switching mechanisms 320_1 to 320_3 is configured to performa switchover between a state where the exhaust gas inlet chamber 310communicates with the outlet opening 340 and a state where the exteriorair inlet chamber 330 communicates with the outlet opening 340.

The exterior air inlet chamber 330 is connected to the switchingmechanisms 320_1 to 320_3, and configured to suck the exterior air andsupply it into the switching mechanisms 320_1 to 320_3. Here, aconfiguration of the exterior air inlet chamber 330 will be describedwith reference to FIG. 10. FIG. 10 is a diagram illustrating aconfiguration of the exterior air inlet chamber 330. FIG. 10schematically depicts horizontal cross section of the exterior air inletchamber 330.

As depicted in FIG. 10, the exterior air inlet chamber 330 includes amain body 331. The main body 331 is a hollow box body, and a multiplenumber of communication openings 332 to 334 communicating with therespective the exterior air suction openings 323 of the switchingmechanisms 320_1 to 320_3 are formed at a side surface of the main body331 which faces the switching mechanisms 320_1 to 320_3. Further, aslit-shaped opening 335 opened along the arrangement direction of thecommunication openings 332 to 334 is formed at a side surface of themain body 331 opposite from the side surface where the communicationopenings 332 to 334 are provided.

The exterior air is introduced into the main body 331 through theopening 335 and then is introduced into one of the switching mechanisms320_1 to 320_3 through the corresponding one of the communicationopenings 332 to 334 after passing through the main body 331.

Here, the opening 335 is formed along the arrangement direction of thecommunication openings 332 to 334. Accordingly, a pressure loss withinthe main body 331 may occur in as uniform a manner as possible, whichwill be described later again. Furthermore, though the opening 335 isformed to have a slit shape in the present exemplary embodiment, theshape of the opening 335 is not limited to the slit shape. For example,the opening 335 may be composed of a multiple number of small holesformed along the arrangement direction of the communication openings 332to 334.

Moreover, the exterior air inlet chamber 330 may have an openingadjuster configured to adjust the opening degree of the opening 335. Theopening adjuster may be a shutter which is fixed to the side surface ofthe main body 331 where the opening 335 is formed, and configured toopen/close the opening 335. As described, by providing the openingadjuster, the pressure loss that occurs within the main body 331 can becontrolled.

Here, the opening 335 is described to be formed at the surface of themain body 331 opposite from the surface where the communication openings332 to 332 are formed. However, the location of the opening 335 may notbe limited thereto as long as the opening 335 is provided at a surfacedifferent from the surface where the communication openings 332 to 334is formed. By way of example, if the communication openings 332 to 334are formed at a side surface of the main body 331, the opening 335 maybe formed at a top surface of the main body 331.

The exterior air suction pipe 350 is a pipeline one end of which isconnected to the second exhaust pipe 200 and the other end of which isopened to the atmosphere (see FIG. 7 to FIG. 9). An exterior air flowrate controller 351 is provided at a portion of the exterior air suctionpipe 350. The exterior air flow rate controller 351 is, for example, adamper, and by varying the opening degree of the damper through adriving unit 352 (see FIG. 7), a flow rate of the exterior air flowingto the one end of the exterior air suction pipe 350 is adjusted. Thedriving unit 352 is controlled by the control unit 18. The exterior airsuction pipe 350 and the exterior air flow rate controller 351 are usedwhen changing an amount of air supply into the processing unit 16.

Further, in the present exemplary embodiment, the one end of theexterior air suction pipe 350 is connected to the second exhaust pipe200. However, the connection position of the one end of the exterior airsuction pipe 350 may not be limited thereto and only needs to be locatedat an upstream side of the switching mechanisms 320_1 to 320_3. By wayof non-limiting example, the one end of the exterior air suction pipe350 may be connected to the exhaust gas inlet chamber 310.

An upstream-side end portion of the differential pressure port 360 isconnected to the one end of the exterior air suction pipe 350, and adownstream-side end portion of the differential pressure port 360 isconnected to the exhaust gas flow rate controller 370. The differentialpressure port 360 is configured to detect a pressure difference betweenthe upstream side and the downstream side and output a detection resultto the control unit 18. The control unit 18 controls the exhaust gasflow rate controller 370 based on the detection result from thedifferential pressure port 360, so that the flow rate of the exhaust gasflown into to the exhaust gas inlet chamber 310 can be maintained at apreset value. Furthermore, the differential pressure port 360 may have athrottle at a portion thereof and may be configured to detect a pressuredifference between the upstream side and the downstream side of thethrottle.

An upstream-side end portion of the exhaust gas flow rate controller 370is connected to the differential pressure port 360, and adownstream-side end portion of the exhaust gas flow rate controller 370is connected to the exhaust gas inlet chamber 310. The exhaust gas flowrate controller 370 accommodates therein, for example, a damper. Theexhaust gas flow rate controller 370 is capable of adjusting the flowrate of the exhaust gas flown into the exhaust gas inlet chamber 310from the differential pressure port 360 by changing the opening degreeof the damper by using a driving unit 371 (see FIG. 8). Further, thedriving unit 371 is controlled by the control unit 18.

Here, as stated above, in the substrate processing system 1 according tothe present exemplary embodiment, the gas exhaust pipe 100 placed on theframe structure 400 is commonly shared by the upper processing unit 16Uand the lower processing unit 16L. In this configuration, the length ofthe second exhaust pipe 200L connected to the processing unit 16L islonger than the length of the second exhaust pipe 200U connected to theprocessing unit 16U. Accordingly, there may be generated a difference inflow resistances of the gas exhaust paths, so that gas exhaust amountsfrom the processing unit 16U and the processing unit 16L may becomenon-uniform.

Meanwhile, the exhaust switching unit 300 according to the exemplaryembodiment is equipped with the differential pressure port 360 and theexhaust gas flow rate controller 370. The control unit 18 controls upperand lower exhaust gas flow rate controllers 370 based on the detectionresults from upper and lower differential pressure ports 360,respectively, so that the gas exhaust amount at the upper side and thegas exhaust amount at the lower side can be made uniform.

Now, an operation of switching the discharge destination of the exhaustgas from the processing unit 16 between the individual exhaust pipes 101to 103 will be explained.

By way of example, FIG. 9 illustrates an example where the alkalineexhaust gas is flown into the individual exhaust pipe 101. In this case,within the exhaust switching unit 300, the exhaust gas suction opening322 of the switching mechanism 320_1 communicates with the exhaust gasinlet chamber 310, and the exterior air suction openings 323 of theother switching mechanisms 320_2 and 320_3 communicate with the exteriorair inlet chamber 330.

That is, while the switching mechanism 320_1 communicates with theexhaust gas inlet chamber 310, the other switching mechanisms 320_2 and320_3 communicate with the exterior air inlet chamber 330. Accordingly,the alkaline exhaust gas is introduced into the individual exhaust pipe101, and exterior air is introduced into the other individual exhaustpipes 102 and 103.

Now, a switchover of the discharge destination of the exhaust gas fromthe individual exhaust pipe 101 to the individual exhaust pipe 102 isassumed. In this case, the control unit 18 controls the driving units326 of the switching mechanisms 320_1 and 320_2 to allow the exhaust gassuction opening 322 of the switching mechanism 320_2 to communicate withthe exhaust gas inlet chamber 310 while allowing the exterior airsuction openings 323 of the other switching mechanisms 320_1 and 320_3to communicate with the exterior air inlet chamber 330. Accordingly, theacidic exhaust gas is introduced into the individual exhaust pipe 102,whereas the exterior air is flown into the other individual exhaustpipes 101 and 103.

As stated above, in the substrate processing system 1 according to theexemplary embodiment, while the exhaust gas from the processing unit 16is introduced into one of the individual exhaust pipes 101 to 103, theexterior air is introduced into the others of the individual exhaustpipes 101 to 103. Accordingly, a flow rate of a gas introduced into eachof the individual gas exhaust pipes 101 to 103 hardly changes before andafter the gas exhaust switching operation is performed. Thus, a pressurevariation of the processing unit 16 that might be accompanied by thechange in the flow rate of the gas can be suppressed.

Moreover, in the substrate processing system 1 according to theexemplary embodiment, by providing, at the front ends of the exteriorair suction openings 323 of the switching mechanisms 320_1 to 320_3, theexterior air inlet chamber 330 communicating with the respectiveexterior air suction openings 323, the pressure variation of theprocessing unit 16 during the gas exhaust switching operation can alsobe suppressed.

Such a mechanism will be elaborated with reference to FIG. 11. FIG. 11illustrates a state during the gas exhaust switching operation.

By way of example, when the discharge destination of the gas exhaust ischanged from the individual exhaust pipe 101 to the individual exhaustpipe 102, the valve body 325 of the switching mechanism 320_1 isslidably moved from a position where it blocks the exterior air suctionopening 323 to a position where it blocks the exhaust gas suctionopening 322. In the meantime, the valve body 325 of the switchingmechanism 320_2 is slidably moved from a position where it blocks theexhaust gas suction opening 322 to a position where it blocks theexterior air suction opening 323. For some time during which thesemovements are made, the exhaust gas suction openings 322 and theexterior air suction openings 323 of the switching mechanisms 320_1 and320_2 are allowed to communicate with the outlet openings 324temporarily.

Here, if the exterior air suction openings 323 of the respectiveswitching mechanisms 320_1 to 320_3 were directly exposed to theatmosphere, a pressure loss in the inlet path of the exterior air wouldbe reduced as compared to a pressure loss in the inlet path of theexhaust gas where the exhaust gas inlet chamber 310 is provided at thefront ends of the exhaust gas suction openings 322. As a result, a flowrate of the exterior air introduced from the exterior air suctionopenings 323, which suffer less pressure loss, is larger than a flowrate of the exhaust gas introduced from the exhaust gas inlet openings322.

If the flow rate of the exterior air introduced into the main bodies 321of the switching mechanisms 320_1 and 320_2 is increased, the flow rateof the exhaust gas introduced into the main bodies 321 from the exhaustgas suction openings 322 is decreased. That is, the flow rate of theexhaust gas during the gas exhaust switching operation is smaller thanflow rates of the exhaust gas before and after the gas exhaust switchingoperation is performed. As a result, an excessive large amount of a gasis suppled into the processing unit 16, so that a leakage of anatmosphere from the processing unit 16 may occur.

Meanwhile, in the substrate processing system 1 according to the presentexemplary embodiment, the exterior air inlet chamber 330 is provided atthe front ends of the exterior air suction openings 323 of therespective switching mechanisms 320_1 to 320_3. Accordingly, adifference between the pressure loss in the inlet path of the exteriorair and the pressure loss in the inlet path of the exhaust gas isreduced, so that it is possible to suppress the flow rate of theexterior air from being increased during the gas exhaust switchingoperation. That is, since a decrease of the flow rate of the exhaust gascan be suppressed during the gas exhaust switching operation, it ispossible to suppress the pressure variation of the processing unit 16which might be caused by the decrease of the flow rate of the exhaustgas.

Furthermore, the respective exhaust gas suction openings 322 of theswitching mechanisms 320_1 to 320_3 communicate with each other via theexhaust gas inlet chamber 310. Likewise, the respective exterior airsuction openings 323 of the switching mechanisms 320_1 to 320_3 alsocommunicate with each other via the exterior air inlet chamber 330.Accordingly, during the gas exhaust switching operation, the exhaust gasinlet chamber 310 and the exterior air inlet chamber 330 are allowed tocommunicate with each other via the switching mechanisms 320_1 to 320_3.

With this configuration, during the gas exhaust switching operation, thepressure variation generated at the side of the inlet path of theexhaust gas can be offset by the pressure variation generated at theside of the inlet path of the exterior air. Thus, the pressure variationof the processing unit 16 during the gas exhaust switching operation canbe effectively suppressed.

Now, a switchover of the discharge destination of the exhaust gas fromthe individual exhaust pipe 102 in which the acidic exhaust gas flows tothe individual exhaust pipe 103 in which the organic exhaust gas flowsis assumed. In this case, the control unit 18 controls the driving units326 of the switching mechanisms 320_2 and 320_3 to allow the exhaust gassuction opening 322 of the switching mechanism 320_3 to communicate withthe exhaust gas inlet chamber 310 while allowing the exterior airsuction openings 323 of the other switching mechanisms 320_1 and 320_2to communicate with the exterior air inlet chamber 330. Accordingly,while the organic exhaust gas is introduced into the individual exhaustpipe 103, the exterior air is flown into the other individual exhaustpipes 101 and 102.

Here, when changing the kind of the processing liquid used in theprocessing unit 16 to IPA, which is the organic processing liquid, thecontrol unit 18, changes by controlling the FFU 21, a gas supply amountinto the processing unit 16 to a second flow rate smaller than a firstflow rate which is set when another kind of processing liquid is used.

If the gas supply amount into the processing unit 16 is reduced, arequired gas exhaust amount is also reduced. In the substrate processingsystem 1 according to the present exemplary embodiment, when changingthe gas supply amount into the processing unit 16 from the first flowrate to the second flow rate, the gas exhaust amount by the exhaustdevices 151 to 153 is not changed, but a difference between the gasexhaust amount by the exhaust devices 151 to 153 and the required gasexhaust amount is supplemented by introducing the exterior air from theexterior air suction pipe 350. This process (hereinafter, referred to as“flow rate adjusting process”) will be described with reference to FIG.12 and FIG. 13. FIG. 12 and FIG. 13 are explanatory diagrams fordescribing the flow rate adjusting process.

FIG. 12 depicts an example where the gas supply amount into theprocessing unit 16 is the first flow rate, and FIG. 13 depicts anexample where the gas supply amount into the processing unit 16 is thesecond flow rate. Further, in the examples of FIG. 12 and FIG. 13, a gasexhaust amount by each of the exhaust devices 151 to 153 is set to be 1m³/min. Further, an initial value of a flow rate of the exterior airintroduced into the differential pressure port 360 from the exterior airsuction pipe 350 is set to be 0 m³/min.

By way of example, when SC1 as the alkaline processing liquid or HF asthe acidic processing liquid is used in the processing unit 16, the gassupply amount into the processing unit 16 is set to the first flow rate(e.g., 1 m³/min), as depicted in FIG. 12. In such a case, a required gasexhaust amount is 1 m³/min, and a difference between the requiredexhaust amount and the exhaust amount by the exhaust devices 151 to 153is 0 m³/min. Accordingly, the flow rate of the exterior air introducedinto the differential pressure port 360 from the exterior air suctionpipe 350 is maintained at 0 m³/min. Here, FIG. 12 illustrates an examplewhere the SC1 as the alkaline processing liquid is used in theprocessing unit 16.

Meanwhile, when IPA as the organic processing liquid is used in theprocessing unit 16, the gas supply amount into the processing unit 16 ischanged from the first flow rate to the second flow rate (e.g., 0.5m³/min), as depicted in FIG. 13. In such a case, a required gas exhaustamount is 0.5 m³/min, and a difference between the required exhaustamount and the exhaust amount by the exhaust devices 151 to 153 is 0.5m³/min. Accordingly, the control unit 18 adjusts the flow rate of theexterior air introduced into the differential pressure port 360 from theexterior air suction pipe 350 to 0.5 m³/min by controlling the exteriorair flow rate controller 351.

As stated above, in the substrate processing system 1 according to thepresent exemplary embodiment, when changing the gas supply amount intothe processing unit 16 from the first flow rate to the second flow ratesmaller than the first flow rate, the flow rate adjusting process ofincreasing the flow rate of the exterior air flown to the one end of theexterior air suction pipe 350 is conducted by controlling the exteriorair flow rate controller 351. Accordingly, it is possible to suppressthe pressure variation of the processing unit 16 while maintaining thegas exhaust amount by the exhaust devices 151 to 153 even when the gassupply amount into the processing unit 16 is changed.

Furthermore, although the present exemplary embodiment has beendescribed for the case where the gas supply amount into the processingunit 16 from the FFU 21 is changed from the first flow rate to thesecond flow rate, the process of changing the gas supply amount from thefirst flow rate to the second flow rate may not be limited to theaforementioned example. By way of non-limiting example, the process maybe applied to a process of changing the kind of a gas supplied into theprocessing unit 16 from a gas (e.g., clean air) supplied by the FFU 21to a gas (e.g., dry gas) supplied by an air supply unit (e.g., ceilingnozzle placed in the FFU 21).

Now, an example of a substrate processing performed in the substrateprocessing system 1 according to the exemplary embodiment will bedescribed with reference to FIG. 14. FIG. 14 is a flowchart fordescribing an example processing sequence of the substrate processingperformed in the substrate processing system 1.

A series of substrate processings described in FIG. 14 are performedunder the control of the control unit 18 over the processing unit 16,the exhaust switching unit 300, and so forth. The control unit 18 isimplemented by, but not limited to, a CPU (Central Processing Unit), andcontrols the processing unit 16, the exhaust switching unit 300, and soforth according to a non-illustrated program stored in the storage unit19.

As depicted in FIG. 14, a first chemical liquid processing is performedin the processing unit 16 (process S101). In this first chemical liquidprocess, the driving unit 33 rotates the holding unit 31, so that thewafer W held on the holding unit 31 is rotated at a preset rotationnumber. Subsequently, the nozzle 41 of the processing fluid supply unit40 is placed above a central portion of the wafer W. Thereafter, thevalve 75 is opened for a preset time, so that SC1 from the alkalineprocessing liquid supply source 71 is supplied onto a processing targetsurface of the wafer W from the nozzle 41. The SC1 supplied on the waferW is diffused onto the entire processing target surface of the wafer Wby a centrifugal force generated by the rotation of the wafer W.Accordingly, the processing target surface of the wafer W is processedwith the SC1.

While this first chemical liquid process is being performed, a gas issupplied from the FFU 21 into the processing unit 16 at a first flowrate. The supply of the gas at the first flow rate is continued until asecond rinsing process of the process S104 is ended. Further, while thefirst chemical liquid process is being performed, the alkaline exhaustgas from the processing unit 16 is discharged from the second exhaustpipe 200 into the individual exhaust pipe 101 through the switchingmechanism 320_1 of the exhaust switching unit 300.

Subsequently, a first rinsing process of cleaning the processing targetsurface of the wafer W with DIW is performed in the processing unit 16(process S102). In this first rinsing process, the valve 78 is openedfor a preset time, so that the DIW from the DIW supply source 74 issupplied onto the processing target surface of the wafer W from thenozzle 41, and the SC1 remaining on the wafer W is washed away by theDIW. While this first rinsing process is being performed, the exhaustgas from the processing unit 16 is discharged into, for example, theindividual exhaust pipe 101.

Then, a second chemical liquid processing is performed in the processingunit 16 (process S103). In this second chemical liquid processing, thevalve 76 is opened for a preset time, so that HF from the acidicprocessing liquid supply source 72 is supplied onto the processingtarget surface of the wafer W from the nozzle 41. The HF supplied on thewafer W is diffused onto the entire processing target surface of thewafer W by the centrifugal force generated by the rotation of the waferW. Accordingly, the processing target surface of the wafer W isprocessed with the HF.

The control unit 18 controls the exhaust switching unit 300 to changethe discharge destination of the exhaust gas from the individual exhaustpipe 101 to the individual exhaust pipe 102 before the second chemicalliquid process is begun. Accordingly, while the second chemical liquidprocess is being performed, the acidic exhaust gas from the processingunit 16 is discharged from the second exhaust pipe 200 into theindividual exhaust pipe 102 through the switching mechanism 320_2 of theexhaust switching unit 300.

Thereafter, in the processing unit 16, the second rinsing process ofcleaning the processing target surface of the wafer W with the DIW isperformed (process S104). In this second rinsing process, the valve 78is opened for a preset time, so that the DIW from the DIW supply source74 is supplied onto the processing target surface of the wafer W fromthe nozzle 41, and the HF remaining on the wafer W is washed away. Whilethis second rinsing process is being performed, the exhaust gas from theprocessing unit 16 is discharged into, for example, the individualexhaust pipe 102.

Then, a drying process is performed in the processing unit 16 (processS105). In this drying process, the valve 77 is opened for a preset time,so that the IPA from the organic processing liquid supply source 73 issupplied onto the processing target surface of the wafer W from thenozzle 41. The IPA supplied on the wafer W is diffused onto the entireprocessing target surface of the wafer W by the centrifugal forcegenerated by the rotation of the wafer W. Accordingly, the DIW remainingon the processing target surface of the wafer W is substituted with theIPA having higher volatility than that of the DIW. Thereafter, in theprocessing unit 16, the rotational speed of the wafer W is increased, sothat the IPA is dispersed off the wafer W, and the wafer W is dried.

The control unit 18 controls the exhaust switching unit 300 to switchthe discharge destination of the exhaust gas from the individual exhaustpipe 102 to the individual exhaust pipe 103 before the drying process isbegun. Accordingly, while the drying process is being performed, theorganic exhaust gas from the processing unit 16 is discharged into theindividual exhaust pipe 103 from the second exhaust pipe 200 through theswitching mechanism 320_3 of the exhaust switching unit 300.

Furthermore, the control unit 18 also changes the gas supply amount fromthe FFU 21 from a first flow rate to a second flow rate smaller than thefirst flow rate. In addition, the control unit 18 controls the exteriorair flow rate controller 351 to increase a flow rate of the exterior airintroduced into the differential pressure port 360 from the exterior airsuction pipe 350. Accordingly, it is possible to suppress the pressurevariation of the processing unit 16 while maintaining the gas exhaustamount by the exhaust devices 151 to 153 even when the gas supply amountinto the processing unit 16 is changed.

Afterwards, in the processing unit 16, the rotation of the wafer W bythe driving unit 33 is stopped, and the wafer W is carried out from theprocessing unit 16 by the substrate transfer device 17 (see FIG. 1).Finally, the series of substrate processings on the single sheet ofwafer W is completed.

As stated above, the substrate processing system 1 (corresponding to anexample of “substrate liquid processing apparatus”) according to thepresent exemplary embodiment includes the processing unit 16(corresponding to an example of “liquid processing unit”), the secondexhaust pipe 200 (corresponding to an example of “exhaust pipe”), theindividual exhaust pipes 101 to 103, and the exhaust switching unit 300(corresponding to an example of “exhaust switching unit”). Theprocessing unit 16 is configured to process the wafer W with a pluralityof processing liquids. The second exhaust pipe 200 is connected to theprocessing unit 16, and an exhaust gas from the processing unit 16 flowswithin the second exhaust pipe 200. The individual exhaust pipes 101 to103 correspond to at least one of the plural kinds of processingliquids. The exhaust switching unit 300 is connected to the secondexhaust pipe 200 and the plurality of individual exhaust pipes 101 to103, and is configured to switch a discharge destination of the exhaustgas flowing within the second exhaust pipe 200 to one of the individualexhaust pipes 101 to 103.

Further, the exhaust switching unit 300 includes the exhaust gas inletchamber 310 and the switching mechanisms 320_1 to 320_3. The exhaust gasfrom the second exhaust pipe 200 is introduced into the exhaust gasinlet chamber 310. The switching mechanisms 320_1 to 320_3 are providedto correspond to the individual exhaust pipes 101 to 103, respectively.Each of the switching mechanisms 320_1 to 320_3 includes the exhaust gassuction opening 322 communicating with the exhaust gas inlet chamber310; the outlet opening 324 communicating with the corresponding one ofthe individual exhaust pipes 101 to 103; the exterior air suctionopening 323 for introducing the exterior air; and the valve body 325configured to switch a communication state of the exhaust gas suctionopening 322, the outlet opening 324 and the exterior air suction opening323 between a state where the exhaust gas suction opening 322communicates with the outlet opening 324 and a state where the exteriorair suction opening 323 communicates with the outlet opening 324.

Accordingly, according to the substrate processing system 1 of theexemplary embodiment, it is possible to suppress the pressure variationof the processing unit 16 during the gas exhaust switching operation.

Modification Examples

Now, modification examples of the substrate processing system 1according to the present exemplary embodiment will be described withreference to FIG. 15 and FIG. 16. FIG. 15 is a schematic side view of aprocessing station according to a first modification example, and FIG.16 is a schematic plan view of the processing station according to thesecond modification example. Further, in the following description, thesame parts as already described above will be assigned same referencenumerals, and redundant description thereof will be omitted.

In the above-described exemplary embodiment, the first exhaust pipe 100is commonly shared by the upper processing units 16U and the lowerprocessing units 16L. However, the substrate processing system may beequipped with an first exhaust pipe 100 for the upper processing unitsand an first exhaust pipe 100 for the lower processing units separately.

By way of non-limiting example, as depicted in FIG. 15, a processingstation 3A according to the first modification example includes a firstexhaust pipe 100U corresponding to the upper processing units 16U and afirst exhaust pipe 100L corresponding to the lower processing units 16L.The first exhaust pipe 100U is equipped with the exhaust switching units300U, and the first exhaust pipe 100L is equipped with the exhaustswitching units 300L.

The first exhaust pipe 100U is placed on the frame structure 400A, andthe first exhaust pipe 100L is placed within the frame structure 400A.To elaborate, the frame structure 400A has an accommodation space foraccommodating the first exhaust pipe 100L and the exhaust switchingunits 300L between a space where upper valve boxes 60 are disposed and aspace where the lower processing units 16L are disposed. The firstexhaust pipe 100L and the exhaust switching units 300L are placed inthis accommodation space.

As stated above, in the processing station 3A according to the firstmodification example, the first exhaust pipe 100U corresponding to theupper processing units 16U is provided above the processing units 16U,and the first exhaust pipe 100L corresponding to the lower processingunits 16L is provided above the processing units 16L and under theprocessing units 16U. That is to say, the first exhaust pipe is disposedabove the processing unit arranged at the corresponding level, and,also, disposed under the processing unit arranged at a level one-levelhigher than the corresponding level.

By adopting this configuration, the length of second exhaust pipes 200Uand the length of second exhaust pipes 200L can be made same at theupper level and the lower level. Accordingly, non-uniformity in the flowresistance of the gas exhaust path may be hardly generated between theprocessing unit 16U and the processing unit 16L. Accordingly, adifference in the gas exhaust amount may be hardly generated between theupper processing unit 16U and the lower processing unit 16L.

Further, in the above-described exemplary embodiment, the first exhaustpipe 100 corresponding to the processing units 16 arranged at thenegative Y-axis side with respect to the transfer section 15 and thefirst exhaust pipe 100 corresponding to the processing units 16 arrangedat the positive Y-axis side with respect to the transfer section 15 areplaced above the regions where the corresponding processing units 16 arearranged, respectively (see FIG. 6). However, the location of the firstexhaust pipe 100 may not be limited to the above example. By way ofexample, a first exhaust pipe 100 may be provided above the transfersection 15, as in a processing station 3B according to the secondmodification example shown in FIG. 16.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting. The scope of the inventive concept is defined by thefollowing claims and their equivalents rather than by the detaileddescription of the exemplary embodiments. It shall be understood thatall modifications and embodiments conceived from the meaning and scopeof the claims and their equivalents are included in the scope of theinventive concept.

We claim:
 1. A substrate liquid processing apparatus, comprising: aliquid processing unit configured to process a substrate with multiplekinds of processing liquids; an exhaust pipe connected to the liquidprocessing unit, and configured to allow an exhaust gas from the liquidprocessing unit to flow therein; a plurality of individual exhaust pipesprovided to correspond to at least one of the multiple kinds ofprocessing liquids; and an exhaust switching unit connected to theexhaust pipe and the individual exhaust pipes, and configured to changea discharge destination of the exhaust gas flowing within the exhaustpipe to one of the individual exhaust pipes, wherein the exhaustswitching unit is positioned above the liquid processing unit.
 2. Asubstrate liquid processing apparatus, comprising: a liquid processingunit configured to process a substrate with multiple kinds of processingliquids; an exhaust pipe connected to the liquid processing unit, andconfigured to allow an exhaust gas from the liquid processing unit toflow therein; a plurality of individual exhaust pipes provided tocorrespond to at least one of the multiple kinds of processing liquids;and an exhaust switching unit connected to the exhaust pipe and theindividual exhaust pipes, and configured to change a dischargedestination of the exhaust gas flowing within the exhaust pipe to one ofthe individual exhaust pipes, wherein the exhaust switching unitcomprises: a plurality of switching mechanisms; and an exterior airinlet chamber which communicates with each of exterior air suctionopenings of the switching mechanisms, and into which exterior air isintroduced.
 3. The substrate liquid processing apparatus of claim 2,wherein the exterior air inlet chamber comprises: a hollow main body; aplurality of communication openings, formed at the main body,communicating with the exterior air suction openings, respectively; andan opening which is formed at a surface of the main body different froma surface where the communication openings are formed, and through whichthe exterior air is introduced into the main body, wherein the openingis formed in an arrangement direction of the communication openings. 4.The substrate liquid processing apparatus of claim 2, furthercomprising: an exterior air suction pipe, one end of which is connectedto an upstream side of the switching mechanisms, and configured tointroduce the exterior air from the other end thereof; and an exteriorair flow rate controller provided on the exterior air suction pipe, andconfigured to adjust a flow rate of the exterior air flowing to the oneend of the exterior air suction pipe.
 5. The substrate liquid processingapparatus of claim 4, further comprising: a control unit configured tocontrol the exterior air flow rate controller to increase the flow rateof the exterior air flowing to the one end of the exterior air suctionpipe, when changing a gas supply amount into the liquid processing unitfrom a first flow rate to a second flow rate smaller than the first flowrate.